In percutaneous revascularization a blood vessel whose interior is occluded by atheromatic material (also called plaque) is treated so that the flow of blood through the artery is increased. The treatment is performed under anesthesia with a fluoroscope to allow the physician to view the procedure. In the case of occluded coronary arteries, the revascularizing device is inserted in the groin area and threaded through the patient's circulatory system to the heart.
In the current state of the art, revascularization is accomplished by balloon angioplasty, laser angioplasty and rotational and directional atherectomy. All these techniques require that as a first step a guide wire be passed through the occlusion. Whether that first step can be accomplished, however is often a function of: (1) the duration (age) of the occlusion; (2) the pathophysiologic mechanism by which the occlusion occurs; and (3) the length of the occlusion. This requirement, to be able to pass a guide wire through a coronary artery occlusion, has been one of the Achilles heels of interventional cardiology. In arteries that are deemed impassable by a guide wire, the cardiologist has had no choice but to perform bypass surgery. This has been the case for patients known to have total or severe occlusions as well as for those whose occlusions are only discovered to be impassable by a guide wire after a revascularization procedure has begun, such as because there is calcification that does not appear on angiography. There are also situations involving arteries that are unusually tortuous or have unusually fragile walls. Bypass surgery, however, is more costly, invasive and complicated than revascularization. Bypass surgery also involves lengthier operating room scheduling, slower recovery time, and higher incidence of increased morbidity and mortality. There is therefore a need for a device that can prepare an impassably occluded artery for revascularization by creating a passage for a guide wire.
There is also a need for a device of this type that is simple to manufacture and simple and quick to use. Such a device should be easy to insert up to an occlusion in a blood vessel, should easily and reliably create a passage for a guide wire through the occlusion in that vessel, and should be easy to withdraw so that a revascularization procedure can be performed.
Guide wires and catheters used for revascularization must travel a long distance in the circulatory system. The physician's control of those devices is remote from the leading or distal end because the control must be accomplished outside the body at the proximal end. Then, too, the arteries of some patients are quite tortuous and the atheromatic material of some patients is quite hard. Because of one or more of such factors, rupture of the artery wall at or near the site of an occlusion may occur. Consequently, there is a need for a simple guide wire passage creation device that includes features to: prevent blood flow should a rupture occur, avoid transmission of unnecessary pressure against the artery wall, and permit physician control over both the direction and the extent of travel of the passage-creating means.